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In this work, a microfluidic chip using Au@SiO2 array–based highly active SERS substrates was developed for quantitative detection of squamous cell carcinoma antigen (SCCA) and carcinoembryonic antigen (CEA) associated with cervical cancer. The chip consisted of six functional units with pump-free design, enabling parallel detection of multiple samples in an automatic manner without external pumps and improving the portability. Ag nanocubes (AgNCs) were labeled with Raman reporters and coupled with antibodies (labeling) to prepare SERS tags, while the Au nanoparticle–modified SiO2 microsphere (Au@SiO2) array was conjugated with antibodies (coating) to generate the highly SERS-active capturing substrate. In the presence of target biomarkers, they were captured by SERS tags and capturing substrate, resulting in the formation of "sandwich" structures which were trapped in the detection chamber. As the immune reaction proceeded, a large number of "hot spots" were generated by the proximity of the Au@SiO2 array substrate and AgNCs, greatly amplifying SERS signals. With this chip, the limits of detection of the SCCA and CEA levels in human serum were estimated to be as low as 0.45 pg mL−1 and 0.36 pg mL−1, respectively. Furthermore, the good selectivity and reproducibility of this chip were confirmed. Finally, clinical serum samples were analyzed by this chip, and the outcomes were consistent with those of enzyme-linked immunosorbent assay (ELISA). Thus, the proposed microfluidic chip can be potentially applied for the clinical diagnosis of cervical cancer. [ABSTRACT FROM AUTHOR]

The detection of dopamine is essential for the treatment and diagnosis of depression and other diseases. In this work, cobalt phosphide nanowire arrays grown on titanium mesh (CoP NWAs/TM) are prepared by two steps of hydrothermal and phosphating, and firstly used for the detection of dopamine. The electrochemical behavior of the CoP NWAs/TM was evaluated by amperometry and differential pulse voltammetry. Amperometric analysis reveals admirable parameters in neutral PBS: (a) a working potential of 0.30 V; (b) a wide linear range (1 μM ~ 3 mM); (c) a high sensitivity (3366 μA·mM−1·cm−2); (d) a low detection limit (3.56 × 10–4 mM). Moreover, the interference effect of the common interfering species and the stability were investigated. Further experiments show that the sensor could be successfully used to detect dopamine in human blood serum. Highly sensitive and selective dopamine sensor uses three-dimensional cobalt phosphide nanowire array, which is the first experiment to apply Co-based transition metal phosphides for dopamine detection. The sensor based on cobalt phosphide nanowire array-electrode could be successfully used to detect dopamine in human blood serum. [ABSTRACT FROM AUTHOR]

Ultrasensitive detection of specific biomarkers in clinical serum is helpful for early diagnosis of cervical cancer. In this paper, a surface-enhanced Raman scattering (SERS)-based immunoassay was developed for the simultaneous determination of squamous cell carcinoma antigen (SCCA) and osteopontin (OPN) in cervical cancer serum. Au-Ag nanoshuttles (Au-AgNSs) as SERS tags and hydrophobic filter paper-based Au nanoflowers (AuNFs) as capture substrate were constructed into a sandwich structure which served as an ultrasensitive SERS-based immunoassay platform. Finite difference time domain simulation confirmed that the electromagnetic field coupled between the AuNFs had a prominent SERS signal enhancement effect, which improved the detection sensitivity. SERS mapping showed that hexadecenyl succinic anhydride hydrophobic treatment could prevent the analyte from being quickly absorbed by the filter paper and increase the retention time to be more evenly distributed on the filter paper substrate. The immunoassay platform was verified to have good selectivity and reproducibility. With this method, the detection limits of SCCA and OPN in human serum were as low as 8.628 pg/mL and 4.388 pg/mL, respectively. Finally, in order to verify the feasibility of its clinical application, the serum samples of healthy subjects; cervical intraepithelial neoplasia I (CINI), CINII, and CINIII; and cervical cancer patients were analyzed, and the reliability of the results was confirmed by enzyme-linked immunosorbent assay experiments. The constructed SERS-based immunoassay platform could be used as a clinical tool for early screening of cancers in the future. [ABSTRACT FROM AUTHOR]

The reduction in Arctic sea ice in summer has been reported to have a significant impact on the global climate. In this study, Arctic sea ice/snow at the end of the melting season in 2018 was investigated during CHINARE-2018, in terms of its temperature, salinity, density and textural structure, the snow density, water content and albedo, as well as morphology and albedo of the refreezing melt pond. The interior melting of sea ice caused a strong stratification of temperature, salinity and density. The temperature of sea ice ranged from −0.8°C to 0°C, and exhibited linear cooling with depth. The average salinity and density of sea ice were approximately 1.3 psu and 825 kg/m3, respectively, and increased slightly with depth. The first-year sea ice was dominated by columnar grained ice. Snow cover over all the investigated floes was in the melt phase, and the average water content and density were 0.74% and 241 kg/m3, respectively. The thickness of the thin ice lid ranged from 2.2 cm to 7.0 cm, and the depth of the pond ranged from 1.8 cm to 26.8 cm. The integrated albedo of the refreezing melt pond was in the range of 0.28–0.57. Because of the thin ice lid, the albedo of the melt pond improved to twice as high as that of the mature melt pond. These results provide a reference for the current state of Arctic sea ice and the mechanism of its reduction. [ABSTRACT FROM AUTHOR]

Nanowires of copper(II)-based metal-organic frameworks (Cu-MOFs) of type Cu(II)(1,4-naphthalenedicarboxylic acid) (1,4-NDC) were deposited on the surface of a copper foam by immersion of Cu(OH)2 nanowires in a solution of 1,4-NDC. An electrochemical immunosensor for the prostate specific antigen (PSA) is obtained by using the nanowire arrays as a redox signal probe. The signal is generated by the conversion of Cu(I) and Cu(II) of Cu-MOFs nanowires. Cu(1,4-NDC) nanowires contain many uncoordinated carboxyl groups which can bind to the amino groups of the PSA antibody. When PSA antibody binds to PSA antigen during an immune response, the current signal will decrease due to the electrical insulation of PSA antigen. The decrease of current is directly proportional to the increase of PSA concentration. The immunosensor, best operated at a voltage of typically −0.08 V (vs. Ag/AgCl), has a low limit of detection (4.4 fg·mL−1) and a wide linear range (0.1 pg·mL−1 to 20 ng·mL−1). This meets the demands of clinical diagnosis (with values <4 ng·mL−1) in serum. The method was applied to the determination of PSA in spiked serum. [ABSTRACT FROM AUTHOR]

Under the background of the rapid development of urban rail transit in China, the development demand of urban underground space has also greatly increased especially in the rail transit station areas. In this paper, taking the high-speed railway station area of Xuzhou Metro Line 1 as an example, the underground space development demand evaluation is conducted by considering the principle of urban underground space stock planning, the local underground space development conditions, as well as the special planning of the local urban constructions. Using the Analytic Hierarchy Process (AHP), a specific weight indicator scale is employed after the rationality of different weight indicator scales being compared. And then the weight indicator of different function types, i.e., commercial, parking, road, etc., are calculated and laterly utilized to forecast the recent development demand of underground space in the station area. Moreover, the steps to forecast the underground space development demand in rail transit station area are proposed, which can provide a reference for the forecasting of underground space development demand in the urban rail transit station areas. [ABSTRACT FROM AUTHOR]

This paper models the relationship between vehicle miles traveled (VMT) on local and collector roads with an objective to predict local road VMT by using collector road VMT. Through a continuous approximation method typically used for vehicle routing, it first analytically reveals this relationship mainly as a function of roadway density ratios between multiple roadway classifications. This structural relationship suggests regression equations using density ratios or logarithmic values of them as the explanatory variables. The use of regression equations enables to account for varying spatial distributions of roadways and demand through parameter calibration. The proposed regression equations are proved good fits through computer simulation using distinct community road network topologies. In addition, practical data from Hennepin County of Minnesota, U.S.A. that encompasses Minneapolis indicates that our developed regression equations can work well. [ABSTRACT FROM AUTHOR]

In this study, we report a surfactant-free and template-free method for the high-yield synthesis of tryptophan and caffeic acid-based resin (TCCR) microspheres for the first time. The method is based on the polymerization reaction of tryptophan and caffeic acid in the formaldehyde aqueous solution to generate resin colloidal microspheres. The Au nanoparticles (AuNPs)-decorated TCCR microspheres prepared by a convenient reduction approach show good stability. AuNPs/TCCR microspheres with a lot of activity groups (amino and hydroxy groups) can not only act as suitable immobilization carriers for antibody but can also play an important role in facilitating the electron transfer. A simple label-free electrochemical multiplexed immunosensor based on AuNPs/TCCR microspheres is developed for simultaneous detection of carcinoembryonic antigen (CEA) and neuron-specific enolase (NSE). Owing to the active group of the AuNPs/TCCR microspheres, the redox molecules [toluidine blue (TB) and Prussian blue (PB)] are absorbed on the surface of these microspheres, which is helpful for absorbing antibodies and signal generation. The prepared TB/AuNPs/TCCR and PB/AuNPs/TCCR microspheres are used as substrate to easily construct electrochemical immunosensor. Under the optimized conditions, the linear range of the proposed immunosensor is estimated to be from 0.2 to 25 ng/mL for both CEA and NSE. At a signal to noise rate of 3, the lowest detectable concentration is 0.11 and 0.08 ng/mL for CEA and NSE, respectively. The assay results of serum samples with the proposed method were in a good agreement with the standard ELISA method. The proposed immunosensor hold great promise for applications in clinical diagnosis, due to the negligible cross-reactivity between the two methods. [ABSTRACT FROM AUTHOR]

Gives information on the difficulty of solving problems completely about electronic configuration assignments of atomic energy levels. Information on artificial neural networks (ANNs); Details of experiments; Results and conclusions of experiments.

The calculations of clusters modeling the fluorine-doping and oxygen deficiency of YBa2Cu307 have been performed by the method of all-electron ab initio Hartree-Fock with self-consistent crystal field. Results show that in CuO planes electric charge significantly increases, the chemical valence of Cu decreases and the covalent bonding of Cu-O greatly weakens owing to oxygen deficiency, while the effect of F restores the local electronic structure of YBa2Cu3O7. The reported opinion that F occupied the oxygen vacancy in Cu-O chains seems disputable according to the calculated bonding characteristics [ABSTRACT FROM AUTHOR]

The taxonomic impediment is characterized by dwindling classical taxonomic expertise, and slow pace of revisionary work, thus more rapid taxonomic assessments are needed. Here we pair rapid DNA barcoding methods with swift assessment of morphology in an effort to gauge diversity, establish species limits, and rapidly disseminate taxonomic information prior to completion of formal taxonomic revisions. We focus on a poorly studied, but diverse spider genus, Pseudopoda, from East Asia. We augmented the standard barcoding locus (COI) with nuclear DNA sequence data (ITS2) and analyzed congruence among datasets and species delimitation methods for a total of 572 individuals representing 23 described species and many potentially new species. Our results suggest that a combination of CO1 + ITS2 fragments identify and diagnose species better than the mitochondrial barcodes alone, and that certain tree based methods yield considerably higher diversity estimates than the distance-based approaches and morphology. Combined, through an extensive field survey, we detect a twofold increase in species diversity in the surveyed area, at 42-45, with most species representing short range endemics. Our study demonstrates the power of biodiversity assessments and swift dissemination of taxonomic data through rapid inventory, and through a combination of morphological and multi-locus DNA barcoding diagnoses of diverse arthropod lineages. [ABSTRACT FROM AUTHOR]